Crown Macromolecular Derivatives: Stepwise Design of New Types of Polyfunctionalized Phosphorus Dendrimers

Phosphorus dendrimers are used for many applications in different domains including nanomedicine as cargo of drugs or as species active per se but also in a variety of other fields ranging from nanoscience to catalysis. Their properties depend on the nature of their internal structure and mainly of the diversity and versatility of the functional groups located on their outer shell. Therefore, there is a need to diversify their structure in order to use them for new applications and to propose alternative synthetic pathways to be built easily, at each step and in high yield a family of original stable phosphorus dendrimers of different generations. Such a goal is illustrated in this report with the original synthesis of 14 new phosphorus dendrimers of generation 0 to 2 and the possibility to modify at will their internal structure and the nature of their functional end groups.

Facial Solid-Phase Synthesis of Well-Defined Zwitterionic Amphiphiles for Enhanced Anticancer Drug Delivery

Serum protein adsorption on the nanoparticle surface determines the biological identity of polymeric nanocarriers and critically impacts the in vivo stability following intravenous injection. Ultrahydrophilic surfaces are desired in delivery systems to reduce the serum protein corona formation, prolong drug pharmacokinetics, and improve the in vivo performance of nanotherapeutics. Zwitterionic polymers have been explored as alternative stealth materials for biomedical applications. In this study, we employed facial solid-phase peptide chemistry (SPPC) to synthesize multifunctional zwitterionic amphiphiles for application as a drug delivery vehicle. SPPC facilitates synthesis and purification of the well-defined dendritic amphiphiles, yielding high-purity and precise architecture. Zwitterionic glycerylphosphorylcholine (GPC) was selected as a surface moiety for the construction of a ultrahydrophilic dendron, which was coupled on solid phase to a hydrophobic dendron using multiple rhein (Rh) molecules as drug-binding moieties (DBMs) for doxorubicin (DOX) loading via pi-pi stacking and hydrogen bonding. The resulting zwitterionic amphiphilic Janus dendrimer (denoted as GPC₈-Rh₄) showed improved stabilities and sustained drug release compared to the analogue with poly(ethylene glycol) (PEG) surface (PEG^5k-Rh₄). In vivo studies in xenograft mouse tumor models demonstrated that the DOX-GPC₈-Rh₄ nanoformulation significantly improved anticancer effects compared to DOX-PEG^5k-Rh₄, owing to the improved in vivo pharmacokinetics and increased tumor accumulation.

Chiral dendrigraft polymer for asymmetric synthesis of isoquinuclidines

A copper complex of chiral modified dendrigraft amidoamine polymer with a pentaerythritol initiated polyepichlorohydrin core, PEN-G₂, on a solid resin support is employed in the synthesis of isoquinuclidines via aza Diels–Alder reaction between cyclohexenone and imines.

Highly functionalized heterogeneous dendrigraft catalysts with peripheral copper moieties for the facile synthesis of 2-substituted benzimidazoles and 2,2-disubstituted benzimidazoles

A highly functionalized heterogeneous copper loaded dendrigraft amidoamine catalyst for the synthesis of 2-substituted and 2,2-disubstituted benzimidazoles is reported.

Multivalency as a key factor for high activity of selective supported organocatalysts for the Baylis-Hillman reaction

The polystyrene-supported N-alkylimidazole-based dendritic catalysts for the Baylis-Hillman reaction exhibit one of the strongest beneficial effects of multivalent architecture ever reported for an organocatalyst. The yields in the model reaction of methyl vinyl ketone with p-nitrobenzaldehyde are more than tripled when a non-dendritic catalyst is replaced by a second- or third-generation analogue. Moreover, the reaction of the less active substrates will not occur with the non-dendritic catalyst and will proceed to a significant extent only with the analogous catalysts of higher generations. A substantial additional enhancement of the reaction yield could be achieved by increasing the content of water in the reaction solvent. The plausible cause of the dendritic effect is the assistance of the second, nearby imidazole moiety in the presumably rate-determining proton transfer in the intermediate adduct, after the first imidazole unit induced the formation of the new carbon-carbon bond.